An attraction at a Las Vegas hotel has temporarily closed after a dolphin died, the third such instance in five months. 

K2, an 11-year-old bottlenose dolphin at the Mirage Secret Garden and Dolphin Habitat on the Las Vegas Strip, died on Saturday, according to a letter Mirage interim President Franz Kallao sent to employees and shared with USA TODAY.

A cause of death was not immediately known, but Kallao said K2 had been receiving treatment for a respiratory illness. The dolphin was born at the attraction.

“All of us are heartbroken over this tragic loss, especially our amazing animal health and care teams who love and care for our animals on a daily basis,” Kallao said. 

K2’s death comes months after two other dolphins died at the facility. Maverick, a 19-year-old bottlenose dolphin, died Sept. 2 after getting treatment for a lung infection, while Bella, a 13-year-old bottlenose dolphin, died in April after undergoing treatment for gastroenteritis. 

According to the international organization Alliance of Marine Mammal Parks and Aquariums’ website, a bottlenose dolphin’s life expectancy in a marine mammal facility is about 28 to 29 years, as life expectancy and survival rates have increased in the past few decades. 

What is the most dangerous animal in the world?:The surprising animal you’ve already met

‘Not a cute animal’: Kangaroo attacks and kills man, blocking paramedics from saving life

As a result, Kallao said Mirage will close the attraction “focus our efforts on ensuring that we have the safest possible environment.” On its website, Mirage says it will remain closed through Oct. 9. 

Outside veterinary, pathology, animal welfare, environmental and other experts will also do a review of the facility and the animals, as well as determine a cause of death. 

“I cannot stress enough that nothing is more important to us than the health, safety and welfare of the animals entrusted in our care,” Kallao said. 

Contributing: Associated Press

Follow Jordan Mendoza on Twitter: @jordan_mendoza5.

What’s everyone talking about?:Sign up for our trending newsletter to get the latest news of the day